docs(01-01): complete HTML scaffold plan — HiDPI canvas, game loop, Player 1 input

- Created 01-01-SUMMARY.md documenting objects built, decisions, patterns
- Updated STATE.md: position advanced to plan 2/2 in Phase 1
- Updated ROADMAP.md: Phase 1 plan 1/2 complete (in progress)
- Marked CORE-07 and VFX-05 requirements as complete in REQUIREMENTS.md

.planning/STATE.md

@@ -2,7 +2,7 @@
 
 **Project Reference**
 - **Core Value:** Pong reimagined with juice and depth — spectacular visuals, rich mechanics, complete game experience
-- **Current Focus:** Roadmap created, ready for Phase 1 planning
+- **Current Focus:** Phase 1 — executing plans
 - **Key Constraint:** Coarse granularity (5 phases max), HTML5 Canvas + vanilla JS, static deployment
 
 ---
@@ -11,13 +11,13 @@
 
 | Attribute | Value |
 |-----------|-------|
-| **Phase** | Planning complete, ready to plan Phase 1 |
-| **Plan** | None active yet |
-| **Status** | Roadmap finalized, 37/37 requirements mapped |
-| **Progress** | 0% (0 phases complete) |
+| **Phase** | 01-foundation |
+| **Plan** | Plan 2/2 (01-02 next) |
+| **Status** | Plan 01-01 complete — scaffold, HiDPI canvas, game loop, Player 1 input done |
+| **Progress** | 5% (1/2 plans complete in Phase 1) |
 
 ```
-[                    ] 0% — Roadmap → Phase 1 planning
+[=                   ] 5% — Phase 1: Plan 1/2 complete
 ```
 
 ---
@@ -29,6 +29,7 @@
 | **Phase Coverage** | 100% (37/37 requirements mapped) | ✓ Complete |
 | **Success Criteria** | 2-5 per phase | ✓ Complete |
 | **Dependency Chain** | Linear (P1 → P2 → P3 → P4 → P5) | ✓ Validated |
+| **01-01 Duration** | — | 1 min (2 tasks, 1 file) |
 
 ---
 
@@ -52,6 +53,14 @@
    - Phase 4: Power-up balance
    - Phase 5: Performance, memory leaks, cross-browser
 
+4. **deltaTime Cap at 50ms:** Game loop caps deltaTime to prevent physics explosion when tab loses focus and resumes — without this a single large delta would fling the ball off screen.
+
+5. **Logical vs Bitmap Coordinate Separation:** canvas.width/height = logical * devicePixelRatio; ctx.scale(dpr, dpr) makes all game draw calls use logical pixels — correct HiDPI approach for sharp rendering on Retina displays.
+
+6. **Module-Object Pattern Established:** GameLoop, Renderer, Input, Physics, GameState are plain JS objects with init() methods in a single script tag. No classes, no modules, no build step — runs directly from filesystem.
+
+7. **e.code over e.key for Input:** Using e.code === 'KeyW' makes W/S detection layout-independent (works on AZERTY and other non-QWERTY keyboards).
+
 ### Coverage Validation
 
 **Total v1 Requirements:** 37
@@ -80,22 +89,24 @@
 
 ### What Just Happened
 
-Roadmap derived from 37 v1 requirements organized into 5 phases, each with 2-5 observable success criteria. Granularity set to coarse; 10-phase research recommendation compressed by grouping related technical work.
+Plan 01-01 executed: Created index.html with full-window HiDPI canvas, Renderer (devicePixelRatio aware), GameLoop (requestAnimationFrame + deltaTime), Input (W/S keys), Physics skeleton (paddle movement + clamping), and GameState. Player 1 paddle is visible and responsive. Requirements VFX-05 and CORE-07 satisfied.
 
 ### What Comes Next
 
-1. `/gsd:plan-phase 1` — Decompose Phase 1 into executable plans
-2. Continue through phases 2-5
-3. Execute plans in dependency order
-4. Validate success criteria at each phase completion
+1. Execute Plan 01-02 — Ball physics: movement, wall bounce, zone-based angle deflection, per-hit speed increment
+2. Continue through phases 2-5 after Phase 1 complete
 
 ### Known Blockers
 
-None. All context available, all requirements mapped, roadmap ready for planning.
+None.
 
 ### Decisions Pending
 
-None. Roadmap finalized; awaiting user approval before phase planning begins.
+None.
+
+### Last Session
+
+Stopped at: Completed 01-01-PLAN.md (2026-03-10)
 
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